The present invention relates to rotary cutters having flexible wings, and more specifically, relates to mechanisms for locking the wings in a folded condition for transport, servicing or storage.
A flex wing rotary cutter must include a locking mechanism for locking the wing(s) up for transporting, servicing and storing the machine. Another requirement is for there to be a solid stop to restrict the wing from being raised past its intended angle. Also, if the cutter is plumbed with a single-acting cylinder acting for controlling the raising and lowering of the wing and is positioned across an incline with the wing raised over center, there is a chance the wing will not lower without assistance. This becomes an inconvenience and is potentially harmful for the operator.
In one known arrangement used to minimize this situation, each wing of the cutter is only raised to about 85xc2x0, but this works on only smaller cutters. On 20xe2x80x2 cutters, for example, a removable stop is required so that the wing can be raised to 90xc2x0 for shipping (the maximum shipping width is 102xe2x80x3). When the cutter reaches its destination, the removable stop must be installed by the dealer to again limit the wing to prevent it from pivoting upward beyond about 85xc2x0.
In other cutter designs, a compression spring or rubber bumper, which is independent of the wing lock mechanism, is used to cushion and stop the wings as they are raised and provide a slight initial force when lowering. These thrust members are located close to the wing hinge point offering a relatively low force to propel the wing down. Furthermore, the lock and stop members are positioned away from each other, therefore imposing unnecessary loading into the structural members that can lead to premature failures. The most common wing lock mechanisms used are either a strap pinned along side the cylinder or a pin that locks the wing to the center section through straps on top of and at the front of the hinge stringers.
According to the present invention, there is provided a flex wing rotary cutter having a new arrangement for controlling the pivoting of each wing.
An object of the invention is to provide a flex wing cutter wherein a single assembly is provided for locking the wing unit in a 90xc2x0 raised position to minimize the transport/shipping width of the cutter, providing a cushioning for the wing unit as it approaches the 90xc2x0 raised position and there providing a positive stop preventing the wing unit from going over center and providing a lowering force that can overcome the weight of the wing when the folded wing is on the upside and the cutter is on an incline.
A more specific object of the invention is to provide a cutter having a wing control arrangement, as set forth in the previous object, wherein the arrangement is in the form of a strut including first and second sections connected together for permitting lost motion between them, a spring for being loaded to resist movement of the wing unit as the strut becomes collapsed as the wing unit approaches a maximum folded position, the loaded spring acting to force the wing unit towards its lowered working position when the lifting force on the wing unit is discontinued and the collapsed strut being selectively fixed in its collapsed condition thus locking the wing unit in its raised position for transport or shipping.
These and other objects will become apparent from a reading of the following description together with the appended drawings.